Pressure and vacuum relief valve



June 20, 1961 H. A. GOODWIN 2,989,073

PRESSURE AND VACUUM RELIEF VALVE Filed May 4, 1956 2 Sheets-Sheet 1 FIG. 2

FIG I INVENTORZ ATTORNEY June 20, 1961 Filed y 1956 FIG. 3

PRESSURE AND VACUUM RELIEF VALVE FIG,5

FIG. 4

H. A. eooD 2 Sheets-Sheet g INVENTOR'.

HARRIS A. GOODWIN Illinois Filed May 4, 1956, Ser. No. 582,741 Claims. (Cl. 137-4933) This invention relates to a pressure and vacuum relief valve, and more particularly to a valve for venting vapor from a transformer to the atmosphere when the pressure in the transformer exceeds a predetermined level and for admitting atmosphere to the transformer when the pressure therein drops below a predetermined level.

When a transformer becomes heated so that the vapor pressure exceeds a predetermined level, the pressure should be vented from the transformer and when the transformer becomes cool so as to create a vacuum condition therein, the vacuum should be relieved by admitting fluid to the transformer.

Heretofore, it has been necessary to accomplish safe pressure stabilization in the transformer by means of frangible disks requiring replacement or by separate valves in separate openings, so that the equipment has been both. expensive to make and maintain and cumbersome to handle or locate in close places. Separate valves have also been subject to misconnection as where an inlet" might be connected where the outlet of the valve should be.

It is accordingly an object of the present invention to provide a pressure and vacuum relief valve in a single compact unit which functions properly regardless of which way it is connected if by design or accident it is not connected in its preferred way.

Another object is to provide a valve of the type indicated in which the vapor pressure of the transformer is applied to one side of each of a pair of diaphragms therein with opposite effectiveness for the diaphragm and atmospheric pressure is applied to the other side of each of the diaphragms, the diaphragm carrying valve means for providing communication between the transformer and the atmosphere when predetermined pressure or vacuum limits for the transformer have been exceeded. This is true regardless of which opening in the unit is connected to the transformer.

Another object of the invention is to provide conduits in the valve means which are effective to transmit a given pressure through the diaphragm from a source which is normally sealed from one side of the diaphragm so that it can be applied on the other side of the diaphragm only. It is this feature of the invention which permits the vapor pressure and the atmospheric pressure to be applied to two diaphragms at the same time so that the diaphragrns are in coactive relationship, with either condition more tightly closing one valve while opening the other.

Another object is to provide means for adjusting the pressure at which the valve is operable.

A further object is to provide a highly sensitive pressure differential control valve and diaphragm assemblies where parts are interchangeable for admitting atmosphere to the transformer when the pressure in the transformer has dropped below a predetermined level, or venting if the pressure rises above a predetermined level, the cooperative arrangement being such that transformer pressure upon the valve side of one diaphragm is effective on the bonnet side of the other diaphragm while atmospheric pressure is present on the other sides of the respective diaphragms.

The invention is characterized by an arrangement in which any condensation occurring in the unit will either drain tov the atmosphere, or to a single collectionpoint where it can be drained from; time to time.

atent Patented June 20, 1961,

ice

Other objects and advantages of the invention will become apparent as the description proceeds in accordance with the drawings in which:

FIG. 1 is a side elevational view of the pressure and vacuum relief valve according to the invention;

FIG. 2 is a vertical sectional view taken through lines 2-2 of FIG. 1;

FIG. 3 is a vertical sectional view taken through lines 3 -3 of FIG. 2;

FIG. 4 is a somewhat diagrammatic sectional view showing the operation of the pressure relief valve means; and

FIG. 5 is a somewhat diagrammatic view showing the operation of the vacuum relief valve means.

Referring now to FIG. l the valve comprises a body portion 12 having two valve compartments 34 and 38 opening on opposite sides thereof and separated by a common wall 41. A bonnet 14 closes compartment 34 as sealed therefrom by a diaphragm 16, and a bonnet 18 closes the other compartment 38 as sealed therefrom by a diaphragm 20, the bonnets 14 and 18- clamping the marginal edges of the diaphragms to the body 12 by a plurality of flange screws 30 threaded into the faces 24 and 28 on the body portion 12.

In order to maintain vapor pressure in a sealed transformer housingor other sealed systems such as airborne f-uel containers (not shown) within predetermined limits in accordance with a pressure differential sensed by each of the'diaphragms 1'6 and 20, the valve 10 is provided with an inlet 32, which in use is connected to the transformer to permit vapor to pass from the transformer into the valve compartment or chamber 34. An outlet passage 36 is formed in the lower end of the valve 10 to place the valve compartment or chamber 38 in open communication with an atmosphere. A bug screen 40 may bethreadedly secured in the outlet passage 36.

In. order to apply atmospheric pressure to the bonnet side of the diaphragm 20 as well as to the chamber side of the diaphragm 16, a cylindrical boss 42 having a conduit 43 therethrough extends from the upper portion of chamber 38 into the vapor chamber 34 where it is closed from the vapor chamber 34 by a hollow valve that communicates with bonnet '18. The hollow valve includes an annular disk 50 carried by a stem 44 secured to the diaphragm 20 to define a conduit 46 which extends through the diaphragm itself. The stem 44 comprises a nipple portion 48 supporting the disk 50 as held in normally sealing relationship against the end of the conduit 42 by the bonnetspring 58. A sleeve 52 threaded to the nipple is slidably received on the conduit 42 in valve guiding relationship. The conduit 42 is preferably reduced at its extremity 54, as is best seen in FIG. 3, and the sleeve 59. is provided with a plurality of radially disposed passages 56 to permit ready flow of fluid when the valve is open as when the pressure in the vapor chamber 34 exceeds the atmospheric pressure in the bonnet 18 by a predetermined amount and moves the diaphragm against the spring 58. The diaphragm 20 will carry the nipple 48 away from conduit 42, as shown in FIG. 4, so that vapor may enter the radial bores 56 and pass through conduit 42 to be vented through outlet opening 36.

Preferably, the valve opens at 8 pounds p.s.i. differential.

The required spring pressure for holding the valve closed until the vapor pressure in chamber 34 has exceeded the pressure in chamber 39 by the given amount is provided by the helical spring 58 where compression for that pressure is adjusted by the spring screw 60' threadedly received in the bonnet 18 and provided with a kerf 62 to receive a screwdriver. The lower end of the spring 58 bears against a diaphragm plate 64, which is held in position on the diaphragm 20 by a diaphragm lock nut 66 threadedly secured on the nipple 48 to hold the valve 44 on the diaphragm. The bonnet 18 in turn is securely sealed by means of a lock nut cap 68 threadedly received on the adjusting screw 60 with a sealing washer 70tdisposed between the cap 68 and the bonnet 18. When it is desired to adjust the pressure on the diaphragm all that needs to be done is to unscrew the cap 68 and rotate the screw 60 for a calibrated amount of angular rotation by means of the kerf 62.

Communication between the chamber 34 and bonnet 14 is had in a similar manner. The pressure present in the chamber 34 is transmitted to the chamber 71 in the bonnet 14 through a cylindrical boss 72, which extends into the atmosphere chamber 38 but is normally sealed therefrom by means of an annular valve 74 carried by the diaphragm 16. The valve 74 has a conduit 76 formed therein corresponding to conduit 46 in valve 34, which cooperates with conduit 72 in providing a continuous passage to the chamber 71. The valve 74 comprises a nipple 76 carrying a disk 78, which is normally biased into sealing engagement with the conduit 72 by means of a helical bonnet spring 80. The spring 80 is compressed by an adjusting screw 82 which bears against a diaphragm plate 84 secured to diaphragm 16 by a lock nut 86, which also serves to fasten the nipple 76 to the diaphragm. A cap 88 is threadedly received on the adjusting screw 82 to seal the bonnet 14 with a washer 90 disposed between the cap 88 and the bonnet.

When the vapor pressure in the bonnet 14 is reduced below a predetermined level such as eight p.s.i. by contraction of the vapor in the transformer resulting, for ex-' ample, from a cooling of the oil in the transformer under winter temperature, the diaphragm 16 will carry the valve 74 away from conduit 72, as best seen in FIG. 5. Air from chamber 38 will then enter conduit 72 through radial bores 92 in a sleeve 94 which is threadedly secured to nipple 76 and slid-ably received on conduit 72. To facilitate this action and reduce the amount of travel required in moving the disk 78 from the end of conduit 72, a reduced portion 6 is also provided on the conduit corresponding to reduced portion 54 on conduit 42.

It is desirable to drain condensate or permit inspection of the quality of the vapor in the transformer at intervals, and for this purpose a gas sampling valve 98 is provided which communicates with chamber 71 by means of a passage 100 in the bonnet 14, and a passage 102 at right angles to the passage 100 which opens into a hose connection 104 having a central passage 106. Although the connection 104 is merely threadedly secured in the lower portion of the bonnet 14 as shown, and a washer 108 is held between the shoulder 110 of the connection and the bonnet the connection may also be soldered after threading together. The passage 100 is normally closed by a valve stem 112 threadedly received in the passage 100 and is adapted to extend beyond the side passage 102 to rest in sealing relation with a valve seat 115. The portion of passage 100 immediately adjacent each side of passage 102 is of substantially the same diameter as valve stem 112, while the portion of passage 100 adjacent chamber 71 is of a reduced diameter to provide the seat 115. Thus when the valve stem 112 is moved inwardly by turning a valve handle 114 thereon, the end of the stem will abut the shoulder 115 in passage 100 in sealing relation thereto. The outer portion of passage 100 is relatively enlarged to receivethe relatively enlarged threaded portion 116 of the stem when the stem is moved axially away from shoulder 115, and a bushing 118 is held in sealing relationship against the outer end of the washer by means of a cap 120 which is threadedly received on an extension 122 of the passage. It will be observed that the passage 100 is located at the lowest point of the unclamped periphery of diaphragm so as to permit drainage of substantially all condensate which may accumulate.

As best shown in FIGS. 4 and 5, the operation of the device is extremely simple. When the vapor pressure is excessive, movement of the valve 44 away from conduit 42 permits vapor to vent through conduit 42 and into the atmosphere through outlet passage 36. correspondingly, when a vacuum condition exists in the transformer, the movement of valve 74 away from conduit 72 permitsatmosphere to enter conduit 72 and thence through inlet 32 into the transformer itself. This operation will be the same even if the valve is connected outlet for inlet by any happenstance.

Accordingly, it will be seen that the conduit 46 in valve 44 permits the vapor pressure in the transformer and in vapor chamber 34 to be applied to one side of each of parting from the spirit of the invention as set forth in the I hereunto appended claims.

I claim:

1. A pressure and vacuum relief valve comprising a body having two valve compartments on opposite sides of a common wall in communication with each other through two conduits, both conduits having inlet ends terminating in opposite compartments in cylindrical bosses terminally defining valve ports, a valve in each compartment having a sleeve telescoping over said cylindrical boss in guided relationship and a nipple closing against the respective valve ports, a diaphragm closing each of said compartments responsive to the pressure therein and connected to said nipple for opening the valve under an increase of pressure in the respective compartments, a bonnet for each diaphragm defining a sealed space above the diaphragm, each nipple having a passageway therethrough in sealed communication with its respective valve port when closed to place the bonnet space of each valve in communication with the compartment of the other valve through the respective conduits, means for urging each valve to its closed position, and conduit means for connecting one compartment to a space whose gauge pressure is to be controlled and venting the other compartment to atmosphere.

2. A pressure and vacuum relief valve comprising a body having two valve compartments on opposite sides of a-common wall in communication with each other through two conduits both of which terminate at one end in raised valve ports in opposite compartments with the other end of one of the conduits located near the lowermost peripheral edge of one of the compartments, a valve in each compartment having a nipple closing against its respective valve port and an element telescoping over its respective valve port, a diaphragm closing each of said compartments responsive to the pressure therein and connected to said nipple for opening the valve under an increase of pressure in the respective compartments, a bonnet for each diaphragm defining a sealed space outwardly of each diaphragm, each nipple having a passageway therethrough in sealed communication with its respective valve port when closed to place the compartment of each valve in communication with the bonnet space of the other valve through the respective conduits, means for urging each valve to its close position, conduit means in said body for connecting said one compartment to a space whose pressure is to be controlled and with said other end of said one conduit disposed lowermost therein to dnain condensation from said one conduit through the nipple cooperating therewith to the bonnet space of that nipple, and valve means for drawing condensate from the last mentioned bonnet space.

3. The combination called for in claim 1 in which the sleeves have lateral apertures therein and the cylindrical bosses are externally reduced in diameter at the valve ports to place the passageway through the respective nipples in communication with the respective compartments through said apertures, said cylindrical bosses and nipples being of substantially the same diameter to support the sleeves in operative position with the conduits and respective nipple passageways in axial alignment at the valve seats.

4. The combination called for in claim 2 in which said compartments and diaphragms are disposed in vertical planes and the conduits disposed substantially horizontally with the other of said compartments vented to the atmosphere.

5. The combination called for in claim 1 in which said conduits are disposed horizontally and are vertically spaced with respect to each other and one of the lowermost conduits open into the compartment of the other conduit at a point adjacent the bottom thereof to drain condensate to the bonnet space of the lowermost valve, and valve means for draining liquid from the bonnet space associated with lowermost valve.

References Cited in the file of this patent UNITED STATES PATENTS 657,891 Donnelly Sept. 11, 1900 942,112 Sprecher Dec. 7, 1909 1,140,565 Belknap May 25, 1915 1,287,119 Shurtleff Dec. 10, 1918 1,703,570 Borch Feb. 26, 1929 2,103,725 Jacobsson Dec. 28, 1937 2,328,007 Griswold Aug. 3, 1943 2,328,010 Griswold Aug. 31, 1943 2,782,800 Hillebrand Feb. 26, 1957 FOREIGN PATENTS 1,091,265 France Oct. 27, 1954 

